Field of the Invention
The invention is generally related to the area of optical communications. In particular, the invention is related to fiber optical switch assembly, and techniques for packaging such an optical switch.
The Background of Related Art
Optical switches are critical building blocks in fiber optical communication networks and other applications. In optical telecommunication, an optical switch is a switch that enables signals in optical fibers to be selectively switched from one end to another. Electromechanical optical switch is one of the commonly used types. It is operated by moving either the ends of input fibers relative to the ends of output fibers, or a mirror/prism to redirect optical signals to a selected output fiber without moving the optical fibers themselves.
Moving a prism is one technique to build a fiber optic switch. As shown in
In most compact 1×2 and 2×2 fiber optic switch designs, the collimators are packaged by soldering processes to a metal substrate or a metal case.
Although there are lead-free solders available now, higher melting temperature to use them can cause the fixation process more stressful, leading to reliability issues. Also many optical components being soldered may not withstand the high temperature that can weaken the reliability of the components. This prompts the industry to rethink if there are alternative approaches to make optical switches.
This section is for the purpose of summarizing some aspects of the present invention and to briefly introduce some preferred embodiments. Simplifications or omissions may be made to avoid obscuring the purpose of the section. Such simplifications or omissions are not intended to limit the scope of the present invention.
Various designs of optical switch are disclosed. According to one aspect of the invention, the optical switch uses wedges to hold up a collimator, where the wedges and the collimator are secured to a substrate with a type of adhesive (e.g., epoxy), thus avoiding high temperature in soldering process. There are at least two assemblies bonded to the substrate using the adhesive. Each of the assemblies includes a collimator and two wedges, where the wedges are provided to physically hold up the collimator in position. The assemblies are glued directly to the substrate after an optical alignment is performed.
Depending on implementation, a common port may be assembled and bonded entirely or partially onto the substrate. A mechanism is also provided to alter an optical path between the common port and either one of the two assemblies. The mechanism is controlled by an actuating device (e.g., a relay or an actuator).
The present invention may be implemented as a method, an apparatus or a part of a system. According to one embodiment, the present invention is an optical switch that comprises: a substrate; at least a first assembly for a common port, the first assembly being bonded to the substrate; a second assembly for a first port, the second assembly being bonded to the substrate; a third assembly for a second port, the third assembly being bonded to the substrate, wherein each of the first, second and third assemblies includes a collimator and at least two wedges, the two wedges provided to hold up the collimator and glued together using a type of adhesive; and a mechanism provided to alter an optical path between the common port to either one of the first port and the second port.
According to another embodiment, the present invention is an optical switch that comprises: an enclosure with a hole on one side thereof; a substrate; at least a first collimator as a common port, the first collimator being accommodated in the hole and glued there through with epoxy; a first assembly for a first port, the second assembly being bonded to the substrate; a second assembly for a second port, the second assembly being bonded to the substrate, wherein each of the first and second assemblies includes a second collimator and at least two wedges, the two wedges provided to hold up the second collimator and glued together using a type of adhesive; and a mechanism provided to alter an optical path between the first collimator to either one of the first port and the second port.
According to still another embodiment, the present invention is a method for manufacturing an optical switch device, the method comprises providing a substrate; making a common port with a first collimator; making a first assembly for a first port, the first assembly being bonded to the substrate after the first assembly is aligned to a specification; making a second assembly for a second port, the second assembly being bonded to the substrate after the second assembly is aligned to the specification, wherein each of the first and second assemblies includes a second collimator and at least two wedges, the two wedges provided to hold up the second collimator and glued together using a type of adhesive; providing a mechanism to alter an optical path between the common port to either one of the first port and the second port.
Other objects, features, and advantages of the present invention will become apparent upon examining the following detailed description of an embodiment thereof, taken in conjunction with the attached drawings.
These and other features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings where:
In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will become obvious to those skilled in the art that the present invention may be practiced without these specific details. The description and representation herein are the common means used by those experienced or skilled in the art to most effectively convey the substance of their work to others skilled in the art. In other instances, well-known methods, procedures, components, and circuitry have not been described in detail to avoid unnecessarily obscuring aspects of the present invention.
Reference herein to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the invention. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Further, the order of blocks in process flowcharts or diagrams representing one or more embodiments of the invention do not inherently indicate any particular order nor imply any limitations in the invention.
Embodiments of the present invention are discussed herein with reference to
Referring now to the drawings, in which like numerals refer to like parts throughout the several views.
As shown in
One of the aspects of the present invention is the use of wedge and epoxy to bond collimators to a substrate completely or partially if the compactness of the switch design cannot allow all three ports to be completely placed within the enclosure.
The fixation of the collimator on a substrate also allows a better reworkability. The wedge can be made in different materials, ranging from quartz, glass, ceramic to metal, etc. In the case of quartz, glass based, UV curing epoxy can be applied due to their UV light transparency features. For ceramic and metal types, one can use the thermally cured epoxy.
Now referring to
A redirect prism 608 is placed between the input and output assembles and is driven by a relay 610, or any other kinds of actuators. When the prism 608 is not in an optical pathway, an optical signal directly goes from the common port 602 to the port1604, or from the port1604 to the common port 602. When the prism 608 is in an optical pathway, the optical signal goes from the common port 602 to the port2606, or from the port2606 to the common port 602.
It may be seen in
At 804 and further at 808, it is assumbled that two assemblies for port1 and port2 are already done and ready to be bonded to the substrate. According to one embodiment, an assembly includes a collimator and two wedges bonded together, where the wedges are used to hold the collimators onto the substrate. Before bonding the assembly for port1 to the substrate, an alignment of the assembly must be performed to ensure that a light beam is coming to or going out from the collimator at a right angle, to minimize possible signal loss. Once the alignment of the assembly for port1 is done, the assembly is boned to the substrate by epoxy at 806. The similar procedure is peformated for the assembley for port2 is done at 810.
At 812, a UV curing process is applied to harden the epoxy, and followed by thermal backing at 814. At 816, a prism or an optical switching mechanism is installed and necessary tests are performed to ensure that the oiptical switching function is achieved to a predefined standard or requirement. At 818, an enclosure is provided to house the substrate along with other parts including a relay used to control the prism or the optical switching mechanism. At 620, a final test is performed.
Optical switches designed in accordance with the present invention are generally adapted to provide high reliability and good switching performance at affordable cost, insert loss are usually below 0.5 dB, over typical working temperature from −5° C. to +70° C. with <0.4 Db TDL, >50 dB return loss, 1260 nm to 1650 nm working wavelength range. The designs and packaging processes are not limited to 1×2 designs, can be extended to 1×N or N×M designs based on different collimator/prism arrangements and layouts.
The present invention has been described in sufficient details with a certain degree of particularity. It is understood to those skilled in the art that the present disclosure of embodiments has been made by way of examples only and that numerous changes in the arrangement and combination of parts may be resorted without departing from the spirit and scope of the invention as claimed. For example, the variable neutral density filter may be replaced by another device that can strengthen an optical signal. Accordingly, the scope of the present invention is defined by the appended claims rather than the foregoing description of embodiments.
Number | Name | Date | Kind |
---|---|---|---|
4852962 | Nicia | Aug 1989 | A |
4859022 | Opdahl et al. | Aug 1989 | A |
4893891 | Fujita | Jan 1990 | A |
5028111 | Yumoto et al. | Jul 1991 | A |
5048912 | Kunikane et al. | Sep 1991 | A |
5305136 | Smith | Apr 1994 | A |
5388172 | Anderson | Feb 1995 | A |
5436986 | Tsai | Jul 1995 | A |
5841917 | Jungerman et al. | Nov 1998 | A |
5867617 | Pan | Feb 1999 | A |
5999669 | Pan et al. | Dec 1999 | A |
6088166 | Lee | Jul 2000 | A |
6134358 | Wu et al. | Oct 2000 | A |
6198857 | Grasis et al. | Mar 2001 | B1 |
6430322 | Al-hemyari | Aug 2002 | B1 |
6437929 | Liu | Aug 2002 | B1 |
6445841 | Gloeckner et al. | Sep 2002 | B1 |
6473544 | Daneman | Oct 2002 | B1 |
6570684 | Stone | May 2003 | B1 |
6665462 | Wu et al. | Dec 2003 | B2 |
6678438 | Chen | Jan 2004 | B2 |
6853505 | Sato et al. | Feb 2005 | B2 |
7058255 | Fang | Jun 2006 | B1 |
7221818 | Cai | May 2007 | B2 |
7672554 | Wang et al. | Mar 2010 | B1 |
20010031111 | Irwin | Oct 2001 | A1 |
20020057864 | Mills | May 2002 | A1 |
20020114556 | Kato et al. | Aug 2002 | A1 |
20020154865 | Lasecki et al. | Oct 2002 | A1 |
20020164113 | Rensing et al. | Nov 2002 | A1 |
20030048982 | Wu et al. | Mar 2003 | A1 |
20030053745 | Chen | Mar 2003 | A1 |
20030095742 | Zhou | May 2003 | A1 |
20030108278 | Chang | Jun 2003 | A1 |
20030123786 | Yee | Jul 2003 | A1 |
20030185498 | Zhou | Oct 2003 | A1 |
20040005111 | Ishikawa et al. | Jan 2004 | A1 |
20040114648 | Nagano et al. | Jun 2004 | A1 |
20040146304 | Kuhara et al. | Jul 2004 | A1 |
20040184718 | Kazama et al. | Sep 2004 | A1 |
20050147354 | Yoon et al. | Jul 2005 | A1 |
20050249454 | Ko | Nov 2005 | A1 |
20060013553 | Imai et al. | Jan 2006 | A1 |
20060198574 | Cai | Sep 2006 | A1 |
20070081762 | Sugiyama et al. | Apr 2007 | A1 |
20080087378 | Washburn et al. | Apr 2008 | A1 |
20120001166 | Doany et al. | Jan 2012 | A1 |
20140253879 | Schuck et al. | Sep 2014 | A1 |